Honda is planning to introduce a range of small-capacity turbo-diesel engines based on the new 1.6-litre i-DTEC unit which will become available in the Civic at the start of next year.
The Japanese company was a late-comer to the diesel market, introducing its first in-house offering – a four-cylinder 2.2 – as late as 2003. That engine has since been re-developed and now appears in a number of Hondas, including the Civic.
But with small-capacity diesels claiming 58 per cent of the European market for Civic-sized cars, something smaller was required.
“The mainstream is shifting towards smaller displacement diesel engines,” says Suehiro Hasshi, the project leader for the Civic i-DTEC development. “There will be a natural evolution of the 2.2 and some improvements, but we will also produce other versions of the 1.6 with different power outputs.”
In the Civic, the new 1.6 provides a class-leading blend of performance and efficiency. It develops 118bhp and 300Nm of torque, but is also potentially capable of 78.5mpg with CO2 emissions of 94g/km.
This is down to a combination of low weight and reduced friction, says Hasshi. The all-aluminium 1.6-litre engine weighs 47kg less than the 2.2, and another 7kg has been saved with the introduction of a new six-speed manual gearbox. At the same time internal friction has been reduced by 40 per cent compared with the 2.2.
Hasshi says the all-new gearbox was essential to get the best from the new engine. “With such a highly sophisticated engine there was no way we were not going to optimise the transmission,” he adds. “The one for the 2.2 engine is not bad, but it was originally designed for our high-torque V6 petrol engines and was not really suitable for the 1.6.”
Honda’s small diesel is just the first of a new range of engines which will replace the entire current line-up over the next three years under the Earth Dreams Technology banner. Honda insiders describe it as their most important new engine in a decade, and say it will soon be powering a quarter of all the cars they sell in the UK.
It has currently been engineered to meet EU5 emissions standards rather than the tougher EU6 regulations due to come into force in September 2015, but Hasshi says this is because the new rules have not yet been fully defined.
“The content of the new legislation has not been fixed 100 per cent,” he says, “so for a manufacturer to say it has an engine which is EU6-compliant does not make sense. The 1.6 can be made EU6-compliant, but the legislation needs to be fixed first.”